Touch-sensitive displays (e.g., touch screens) allow users to input commands and data directly into a display, which is particularly useful in various applications. Such touch screen applications include various consumer products, including cellular telephones and user interfaces for industrial process control. Depending on the specific application, these touch-sensitive displays are commonly used in devices ranging from small handheld PDAs, to medium sized tablet computers, to large industrial implements.
It is often convenient for a user to input and read data on the same display. Unlike a dedicated input device, such as a keypad with discrete and tactilely distinguishable keys, most touch-sensitive displays generally define a flat and continuous input surface providing no significant tactile guidance to the user. Instead, touch-sensitive displays rely on visual cues (e.g., displayed images) to guide user inputs.
A serious drawback of touch-sensitive displays is thus the inherent difficulty a user faces when attempting to input data accurately because adjacent buttons are not distinguishable by feel. Improper keystrokes are common, which forces the user to focus both on the keypad (to properly input the next keystroke) and on the text input line (to check for errors); generally, the user is forced to keep his or her eyes on the display in order to minimize input errors. The importance of tactile guidance is readily apparent in the competition between the Apple's iPhone and RIM's BlackBerry 8800. Touch-sensitive displays and physical hard buttons each have benefits and drawbacks, and digital devices generally incorporate one such component or the other, although some devices do include both disparate components, which often makes for either bulkier devices or devices with less operating power due to size constraints.
As with many touch sensitive displays, nearly any touch on the display surface is registered as an input; this substantially prevents the user from resting a finger or palm on the touch surface while generating proper inputs (such as typing). Furthermore, some touch sensitive displays rely on capacitance changes due to the presence of a finger at a location on the touch surface to indicate a user input, and these devices do not sense user inputs when a barrier exists between a finger of the user and the touch surface, such as when the user is wearing a glove.
Thus, there is a need in the touch-based interface field to create a new and useful interface that incorporates tactile guidance for one or more control buttons and/or incorporates alternatives to sensing a user input. This invention provides such an interface and associated method.